1. Field of the Invention
This invention relates to magnetic recording and more particularly, to magnetic amorphous alloys having particular utility in the field of magnetic recording and having a high magnetic flux density.
2. Description of the Prior Art
In the field of magnetic recording, there is a recent trend toward high density recording, for which magnetic recording mediums having high coercive force have been manufactured. Recording heads for the high density recording should have magnetic cores made of materials which satisfy a number of characteristic requirements. For instance, the core materials should have a high saturation magnetic flux density, Bs, a small coercive force, Hc, a high magnetic permeability, .mu., good stability in magnetic characteristics against external stress, good resistances to abrasion, corrosion and heat, and easy processing. One of typical high density recording systems is a vertical magnetic recording system. In the vertical magnetic recording system, Co-Cr alloys have been usually used as a magnetic layer of a vertical magnetic medium. Such alloys have usually a saturation magnetic flux density, Bs, of about 6000 gausses. In order to record information signal on the medium having such a level of Bs as mentioned above, a core material for the recording head should have a saturation magnetic flux density, Bs, as high as 10,000 gausses or higher. However, hitherto known magnetic materials do not satisfy all the characteristic requirements mentioned above. For instance, Permalloy materials are unsatisfactory because their saturation magnetic flux density is as low as 7000-8000 gausses. With metal-metalloid alloys such as amorphous Co-Fe-Si-B alloys, they have a satisfactorily high saturation magnetic flux density, Bs, but are thermally unstable, thus leading to the disadvantage that magnetic characteristics vary largely as a function of time.